51.
Issa, Mohamed, et al.
(författare)
Targeted gene delivery with trisaccharide-substituted chitosan oligomers in vitro and after lung administration in vivo
2006
Ingår i: Journal of Controlled Release. - : Elsevier BV. - 0168-3659 .- 1873-4995. ; 115:1, s. 103-112
Tidskriftsartikel (refereegranskat) abstract
The aim of this study was to improve the gene delivery efficacy of chitosan oligomer polyplexes by introducing a trisaccharide branch that targets cell-surface lectins. For this purpose, chitosan oligomers were substituted by a trisaccharide with the N-acetylglucosamine residue at the free end, and the ability of the trisaccharide-substituted chitosan oligomers (TCO) polyplexes to transfect various cell lines in vitro and lung tissue after in vivo administration to mice was investigated. Live-cell confocal microscopy showed improved cellular uptake in HEK 293 cells (11-fold, p < 0.001) for the TCO polyplexes compared with the linear chitosan oligomers. Colloidal stability was also enhanced with the substituted form, which suggests that the trisaccharide branch stabilised the polyplexes by means of a steric stabilisation mechanism. Interestingly, gene expression levels in the human liver hepatocyte (HepG2) cells were 10-fold higher with the TCO polyplexes than those mediated by polyethyleneimine. A similar improvement was obtained in a human bronchial epithelial cell line (16HBE14o-). Transfection with the TCO was significantly inhibited (by 30-80%). for all the cell lines tested, in the presence of the free trisaccharide branch, confirming lectin-mediated uptake. Finally, in vivo studies showed that, 24 h after lung administration to mice, luciferase gene expression was 4-fold higher with the TCO than with the corresponding linear chitosan oligomers.
52.
Jansson, Britt, et al.
(författare)
Enantiospecific separation and quantitation of mephenytoin and its metabolites nirvanol and 4'-hydroxymephenytoin in human plasma and urine by liquid chromatography/tandem mass spectrometry
2006
Ingår i: Rapid Communications in Mass Spectrometry. - : Wiley. - 0951-4198 .- 1097-0231. ; 20:3, s. 463-572
Tidskriftsartikel (refereegranskat) abstract
A sensitive method using enantiospecific liquid chromatography/tandem mass spectrometry detection for the quantitation of S- and R-mephenytoin as well as its metabolites S- and R-nirvanol and S- and R-4'-hydroxymephenytoin in plasma and urine has been developed and validated. Plasma samples were prepared by protein precipitation with acetonitrile, while urine samples were diluted twice with the mobile phase before injection. The analytes were then separated on a chiral alpha(1)-acid glycoprotein (AGP) column and thereafter detected, using electrospray ionization tandem mass spectrometry. In plasma, the lower limit of quantification (LLOQ) was 1 ng/mL for S- and R-4'-hydroxymephenytoin and S-nirvanol and 3 ng/mL for R-nirvanol and S- and R-mephenytoin. In urine, the LLOQ was 3 ng/mL for all compounds. Resulting plasma and urine intra-day precision values (CV) were <12.4% and <6.4%, respectively, while plasma and urine accuracy values were 87.2-108.3% and 98.9-104.8% of the nominal values, respectively. The method was validated for plasma in the concentration ranges 1-500 ng/mL for S- and R-4'-hydroxymephenytoin, 1-1000 ng/mL for S-nirvanol, and 3-1500 ng/mL for R-nirvanol and S- and R-mephenytoin. The validated concentration range in urine was 3-5000 ng/mL for all compounds. By using this method, the metabolic activities of two human drug-metabolizing enzymes, cytochrome P450 (CYP) 2C19 and CYP2B6, were simultaneously characterized.
53.
Johansson, Gunnar, et al.
(författare)
Cost effectiveness of budesonide/formoterol for maintenance and reliever therapy versus salmeterol/fluticasone plus salbutamol in the treatment of asthma
2006
Ingår i: PharmacoEconomics (Auckland). - : Springer Science and Business Media LLC. - 1170-7690 .- 1179-2027. ; 24:7, s. 695-708
Tidskriftsartikel (refereegranskat) abstract
INTRODUCTION: Budesonide/formoterol (Symbicort) Maintenance And Reliever Therapy (SMART) is an effective and well tolerated treatment option for patients with asthma. We compared the cost effectiveness from a societal perspective of this one-inhaler regimen with that of maintenance salmeterol/fluticasone propionate (Seretide) plus salbutamol (albuterol) as needed (Seretide) Fixed Combination [SFC]). STUDY DESIGN: A cost-effectiveness analysis was performed based on effectiveness and resource-utilisation data collected prospectively in a randomised, 12-month study performed in 2143 patients in 16 countries. Resource utilisation data were pooled and unit costs (euro, year 2003 values) from Italy, France, the UK and Germany were used to generate estimates of direct and total costs per patient per year and cost per severe exacerbation avoided. METHODS: Adolescents and adults with asthma (n = 2143; mean forced expiratory volume in 1 second [FEV(1)] 73% predicted; mean inhaled corticosteroid [ICS] dose 884 microg/day) were randomised to SMART or SFC. The effectiveness measure used was the number of severe exacerbations per patient per year. Direct costs included medication use (budesonide/formoterol 160microg/4.5microg or salmeterol/fluticasone 50microg/100microg, 50microg/250microg or 50microg/500microg plus salbutamol) and nonmedication-related resource use, including days in hospital, emergency room visits, specialist or primary care physician visits and other healthcare provider contacts. Indirect costs, including the number of days when the patient or their carer was unable to attend to their normal daily activities, were also assessed. The study assumed a European societal perspective (i.e. including direct and indirect costs). RESULTS: Treatment with SMART resulted in significantly fewer severe exacerbations per patient per year compared with SFC (0.24 vs 0.31 events per patient per year; p = 0.0025). Resource use was low in both groups. Medication costs accounted for the majority of the total costs. The increased effectiveness of SMART was achieved at a reduced or similar cost compared with SFC. SMART dominated when German unit costs were applied (i.e. there was a statistically significant reduction in both costs and number of exacerbations). In all other countries, the incremental cost-effectiveness ratios showed that there was a reduction in mean total cost per exacerbation avoided; however, this difference was not statistically significant. CONCLUSION: This analysis demonstrates that, compared with SFC, SMART may be cost effective from a societal perspective for the treatment of patients with asthma in Italy, Germany, France and the UK. SMART provided a reduction in the number of severe exacerbations per patient per year, at no statistically significant increase in cost - or even at a lower cost - compared with SFC plus as-needed reliever salbutamol.
54.
55.
Jonson, Rebecca, 1976
(författare)
Dialogue Context-Based Reranking of ASR Hypotheses
2006
Ingår i: SLT 2006 : 2006 IEEE ACL Spoken Language Technology Workshop : proceedings : December 10-13, 2006, Aruba Marriott, Palm Beach, Aruba. - 1424408733 ; , s. 174-177
Konferensbidrag (refereegranskat)
56.
Karlsson, Krister, et al.
(författare)
Chromatographic characterization of substance P endopeptidase in the rat brain reveals affected enzyme activity following heat stress
2006
Ingår i: Biomedical Chromatography. - : Wiley. - 0269-3879 .- 1099-0801. ; 20:1, s. 77-82
Tidskriftsartikel (refereegranskat) abstract
This paper describes a study of substance P endopeptidase (SPE)-like activity in various regions of the brain from male rats subjected to heat stress (HS). The enzyme activity was found to be affected in several brain areas including cerebellum, cerebral cortex, hippocampus, hypothalamus[sol ]thalamus and the spinal cord following HS. Significant increases in SPE activity were observed in, for example, hippocampus and the spinal cord. SPE-containing extracts from hippocampus were pooled and subsequently purified by size exclusion chromatography (using a Superdex® 75 HR column) and by anion-exchange chromatography (using Resource Q® column). The gel permeation chromatography separated the SPE-like activity into two fractions, one of which was suggested to be identical to neutral endopeptidase owing to its molecular size and inhibitory profile. The other active enzyme fraction behaved in conformity with SPE, previously identified in human cerebrospinal fluid. The activity of the purified fraction of these two enzymes was found to be increased (27%) in HS-treated animals.
57.
Kloft, Charlotte, et al.
(författare)
Population pharmacokinetic-pharmacodynamic model for neutropenia with patient subgroup identification : comparison across anticancer drugs
2006
Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 12:18, s. 5481-5490
Tidskriftsartikel (refereegranskat) abstract
Purpose: Cancer chemotherapy, although based on body surface area, often causes unpredictable myelosuppression, especially severe neutropenia. The aim of this study was to evaluate qualitatively and quantitatively the influence of patient-specific characteristics on the neutrophil concentration-time course, to identify patient subgroups, and to compare covariates on system-related pharmacodynamic variable between drugs. Experimental Design: Drug and neutrophil concentration, demographic, and clinical chemistry data of several trials with docetaxel (637 patients), paclitaxel (45 patients), etoposide (71 patients), or topotecan (191 patients) were included in the covariate analysis of a physiology-based pharmacokinetic-pharmacodynamic neutropenia model. Comparisons of covariate relations across drugs were made. Results: A population model incorporating four to five relevant patient factors for each drug to explain variability in the degree and duration of neutropenia has been developed. Sex, previous anticancer therapy, performance status, height, binding partners, or liver enzymes influenced system-related variables and alpha(1)-acid glycoprotein, albumin, bilirubin, concomitant cytotoxic agents, or administration route changed drug-specific variables. Overall, female and pretreated patients had a lower baseline neutrophil concentration. Across-drug comparison revealed that several covariates (e.g., age) had minor (clinically irrelevant) influences but consistently shifted the pharmacodynamic variable in the same direction. Conclusions: These mechanistic models, including patient characteristics that influence drug-specific parameters, form the rationale basis for more tailored dosing of individual patients or subgroups to minimize the risk of infection and thus might contribute to a more successful therapy. In addition, nonsignificant or clinically irrelevant relations on system-related parameters suggest that these covariates could be negligible in clinical trails and daily use.
58.
Kopanchuk, Sergei, et al.
(författare)
Kinetic evidence for tandemly arranged ligand binding sites in melanocortin 4 receptor complexes
2006
Ingår i: Neurochemistry International. - : Elsevier BV. - 0197-0186 .- 1872-9754. ; 49:5, s. 533-542
Tidskriftsartikel (refereegranskat) abstract
The melanocortin 4 receptor (MC(4)R) binding of the peptide analogue of melanocyte stimulating hormone, [(125)I]NDP-MSH, and the low molecular weight radionucleid 1-(D-1,2,3,4-tetrahydroisoquinoline-3-carboxy-D-4-(125)iodophenylalanyl)-4-cyclohexyl-4-[(1,2,4-triazol-1-yl)methyl]piperidine trifluoroacetate ([(125)I]THIQ) were compared. Kinetic analysis indicated heterogeneity in the binding of both radioligands, the binding apparently proceeding to two tandemly arranged interconnected mutually dependent binding sites. Steric considerations and BRET analysis of Rluc and GFP tagged receptors proposed that these sites are located on different subunits of receptor dimers, which form receptor complexes. According to the minimal model proposed, ligand binding proceeds consecutively to the two binding sites of the dimer. After binding of the first ligand conformational transformations of the complex occur, which is followed by binding of the second ligand. When both receptor units have bound [(125)I]NDP-MSH, the radioligand can be released only from one unit. The [(125)I]NDP-MSH bound to the remaining unit stays practically irreversibly bound due to a very slow retransformation rate of the transformed complex. The considerably faster binding of [(125)I]THIQ did not allow accurate kinetic differentiation of the two binding sites. However, addition of NDP-MSH as well as a fragment of the human agouti protein, hAGRP(83-132) to the preformed [(125)I]THIQ-MC(4)R complex drastically retarded the release of [(125)I]THIQ from the complex, blocking conformational transformations in the complex by binding into the second binding site. The consecutive binding of ligands to the MC(4)R dimers has substantial impact on the apparent ligand potencies, when determined in competition with the two different radioligands applied herein; the apparent potencies of the same ligand differing up to three orders of magnitude when assayed in competition with [(125)I]NDP-MSH or [(125)I]THIQ.
59.
Kultima, Kim, et al.
(författare)
Cadmium-induced gene expression changes in the mouse embryo, and the influence of pretreatment with zinc
2006
Ingår i: Reproductive Toxicology. - : Elsevier BV. - 0890-6238 .- 1873-1708. ; 22:4, s. 636-646
Tidskriftsartikel (refereegranskat) abstract
Cadmium (Cd) administered to female C57BL/6 mice on gestation day 8 induces a high incidence of anterior neural tube defects (exencephaly). This adverse effect can be attenuated by maternal pretreatment with zinc (Zn). In this study we used replicated microarray analysis and real-time PCR to investigate gene expression changes induced in the embryo 5 and 10h after maternal Cd exposure in the absence or presence of Zn pretreatment. We report nine genes with a transcriptional response induced by Cd, none of which was influenced by Zn pretreatment, and two genes induced only by combined matemal Cd exposure and Zn pretreatment. We discuss the results in relation to the possibility that Cd is largely excluded from the embryo, that the teratogenic effects of Cd may be secondary to toxicity in extraembryonic tissues, and that the primary protective role of Zn may not be to reverse Cd-induced transcription in the embryo.
60.
Kultima, Kim, et al.
(författare)
Normalization and expression changes in predefined sets of proteins using 2D gel electrophoresis : A proteomic study of L-DOPA induced dyskinesia in an animal model of Parkinson's disease using DIGE
2006
Ingår i: BMC Bioinformatics. - : Springer Science and Business Media LLC. - 1471-2105. ; 7, s. 475-
Tidskriftsartikel (refereegranskat) abstract
Background: Two-Dimensional Difference In Gel Electrophoresis (2D-DIGE) is a powerful tool for measuring differences in protein expression between samples or conditions. However, to remove systematic variability within and between gels the data has to be normalized. In this study we examined the ability of four existing and four novel normalization methods to remove systematic bias in data produced with 2D-DIGE. We also propose a modification of an existing method where the statistical framework determines whether a set of proteins shows an association with the predefined phenotypes of interest. This method was applied to our data generated from a monkey model (Macaca fascicularis) of Parkinson's disease. Results: Using 2D-DIGE we analysed the protein content of the striatum from 6 control and 21 MPTP-treated monkeys, with or without de novo or long-term L-DOPA administration. There was an intensity and spatial bias in the data of all the gels examined in this study. Only two of the eight normalization methods evaluated ('2D loess+scale' and 'SC-2D+quantile') successfully removed both the intensity and spatial bias. In 'SC-2D+quantile' we extended the commonly used loess normalization method against dye bias in two-channel microarray systems to suit systems with three or more channels. Further, by using the proposed method, Differential Expression in Predefined Proteins Sets (DEPPS), several sets of proteins associated with the priming effects of L-DOPA in the striatum in parkinsonian animals were identified. Three of these sets are proteins involved in energy metabolism and one set involved proteins which are part of the microtubule cytoskeleton. Conclusion: Comparison of the different methods leads to a series of methodological recommendations for the normalization and the analysis of data, depending on the experimental design. Due to the nature of 2D-DIGE data we recommend that the p-values obtained in significance tests should be used as rankings only. Individual proteins may be interesting as such, but by studying sets of proteins the interpretation of the results are probably more accurate and biologically informative.
